1. Field of the Invention
The present invention relates to an ophthalmic image sensing apparatus such as a fundus camera used in fundus examinations such as a mass health examination.
2. Related Background Art
As disclosed in Japanese Patent Application Laid-Open No. H10-75932 official gazette and Japanese Patent Application Laid-Open No. H10-113336, in mass health examinations such as a resident medical examination and a company medical examination, fundus examinations are implemented respectively. Although fundus image sensing of only one eye was performed before, since a finding may have appeared in the other eye which has not been examined, right and left eye image sensing has implemented in recent years.
In fundus image sensing in a mass health examination, non-mydriasis image sensing which does not need a mydriatic is performed usually. The non-mydriasis image sensing is performed after urging the natural mydriasis of an eye to be examined, by making the inside of an inspecting room dark, or covering a head including an eye to be examined from indoor light by a simple darkroom or the like.
In addition, although a roll of 35 mm film, a Polaroid film or the like has been used for the recording of a sensed image up to now, a method of recording as a digital image using a sensor, such as a CCD, has gone mainstream in recent years. Generally, in this digital image recording, there is an advantage that there may be low image sensing light intensity from the difference of sensitivity of image sensing apparatuses in comparison with silver halide film recording.
Hence, since there is little effect of miosis after image sensing when a digital image recording system is used, it becomes possible to sense images of right and left eyes in a shorter time in comparison with a silver halide film recording system.
However, since being non-mydriasis image sensing cannot disregard the effect of the miosis after image sensing, when right and left eye image sensing is performed continuously, there is a problem that an image of an eye to be examined which is image sensed later becomes dark. For this reason, when an image of the other eye is sensed after the completion of a first image sensing, image sensing light intensity is adjusted so that the image of the other eye may be kept from becoming dark in the former.
Thereby, there has arisen a trouble that it has been forgotten to return the adjusted light intensity in the case that another person to be examined has taken the place, or the like. In addition, also as to the adjustment intensity of image sensing light intensity, since a camera person sets it by experience, difference appears in the quality of a sensed image by the presence of experience, or even if he/she is an experienced person, it is said that it is difficult to set proper image sensing light intensity from a state of a pupil which changes with time.
As stated also in advance, usually, non-mydriasis image sensing for which the fundus image sensing mentioned above does not need a mydriatic is performed. In the non-mydriasis image sensing, a darkroom, a simple darkroom which covers only a head, including an eye to be examined, from indoor light, or the like are used, and fundus image sensing is performed with making the eye to be examined natural mydriasis. Although a roll of 35 mm film, an instant film or the like has been used for the recording of a sensed image up to now, a method of recording as a digital image using a sensor, such as a CCD, has gone mainstream in recent years. Generally, in digital image recording, there is an advantage that low image sensing light intensity is required from the difference of sensitivity of image sensing apparatuses in comparison with silver halide film recording. Hence, since there is little effect of miosis after image sensing when a digital image recording system is used, it becomes possible to sense images of right and left eyes in a shorter time in comparison with a silver halide film recording system.
In addition, in order to observe a papilla region three-dimensionally (stereoscopically) for glaucomatous diagnosis, temporal stereography of sensing two images with shifting the two images by certain baseline length within a pupil is also performed. Furthermore, in order to be able to observe a fundus image at once to a peripheral part of a fundus of an eye, it is performed to create one panorama fundus image by sensing 3 to 8 images with changing a fixation position by shifting a position of a fixation lamp of a fundus camera, and pasting the images together.
However, even if image sensing is performed in low image sensing light intensity so as to sense images in a state of non-mydriasis, it is not possible to disregard the effect of miosis after image sensing. Hence, when the image sensing of the same eye to be examined is performed continuously, the fundus images may become darker as the times increase. For this reason, it may be necessary to adjust the image sensing light intensity before next image sensing is performed after the end of a first image sensing.
In addition, also when performing solid image sensing and image sensing for panorama creation in the state of non-mydriasis, an experience may be needed for the adjustment of the image sensing light intensity due to miosis in the second image sensing rather than the first image sensing.